- or P/M - is a highly developed method of manufacturing reliable ferrous
and nonferrous parts. Made by mixing elemental or alloy powders and
compacting the mixture in a die, the resultant shapes are then sintered or
heated in a controlled-atmosphere furnace to bond the particles
metallurgically. Basically a "chipless" metalworking process, P/M
typically uses more than 97% of the starting raw material in the finished
part. Because of this, P/M is an energy and materials conserving process.
process is cost effective in producing simple or complex parts at, or very
close to, final dimensions in production rates which can range from a few
hundred to several thousand parts per hour. As a result, only minor, if
any, machining is required. P/M parts also may be sized for closer
dimensional control and /or coined for both higher density and strength.
parts weigh less than 5 pounds (2.27 kg), although parts weighing as much
as 35 pounds (15.89 kg) can be fabricated in conventional P/M equipment.
Many of the early P/M parts, such as bushings and bearings, were very
simple shapes, as contrasted with the complex contours and multiple levels
which are often produced economically today.
Advantages of the P/M Process
Eliminates or minimizes machining
Eliminates of minimizes scrap losses
Maintains close dimensional tolerances
Permits a wide variety of alloy systems
Produces good surface finishes
Provides materials which may be heat-treated for increased strength or
increased wear resistance
Provides controlled porosity for self-lubrication or filtration
Facilitates manufacture of complex or unique shapes which would be
impractical or impossible with other metalworking processes
Suited to moderate -to high volume components production requirements
Offers long-term performance reliability in critical applications